Add /_dendrite/admin/evacuateRoom/{roomID} (#2401)

* Add new endpoint to allow admins to evacuate the local server from the room

* Guard endpoint

* Use right prefix

* Auth API

* More useful return error rather than a panic

* More useful return value again

* Update the path

* Try using inputer instead

* oh provide the config

* Try that again

* Return affected user IDs

* Don't create so many forward extremities

* Add missing `Path` to name

Co-authored-by: Till <2353100+S7evinK@users.noreply.github.com>

roomserver/api/api.go

@@ -66,6 +66,12 @@ type RoomserverInternalAPI interface {
 		res *PerformInboundPeekResponse,
 	) error
 
+	PerformAdminEvacuateRoom(
+		ctx context.Context,
+		req *PerformAdminEvacuateRoomRequest,
+		res *PerformAdminEvacuateRoomResponse,
+	)
+
 	QueryPublishedRooms(
 		ctx context.Context,
 		req *QueryPublishedRoomsRequest,